1. Field of the Invention
The present invention relates to magnetic ink character recognition (MICR) systems, and more particularly to a MICR system wherein each character field is divided into a plurality of discrete lines or segments that are individually magnetizable preparatory to character recognition.
2. Description of the Prior Art
Magnetic ink character recognition involves two fundamental steps in the recognition process. First, the magnetizable ink forming a recognizable character must be magnetized to create a magnetic image of the character; and secondly, the magnetic image must be sensed or read and identified as a character in accordance with pattern recognition techniques.
Focusing on the first step of the recognition process, the character field is generally divided into a plurality of discrete, vertical lines or segments, each line or segment being individually magnetized. A common magnetization technique is to apply a sinusoidally-varying magnetic field over the character, where each sinusoidal cycle is intended to magnetize one discrete segment of the character. This technique has been shown by experience to facilitate the reading and recognition of the character.
In practice, when a document bearing encoded characters of magnetizable ink is magnetized or written upon, it is transported past a write station having a write head that generates the sinusoidally varying magnetic field. The transportation of the document past the write station is generally by mechanical means, such as by a read drum having an outer circumferential edge that grips the document and rotationally transports it past both the write and read stations. It is important that the mechanical transport means be driven at a uniform, consistent velocity to correlate the position of the character field in the write station with the timed actuation of the write head for properly spaced magnetization to occur.
This requirement of consistent, uniform transport velocity necessitates the use of highly precise, low-tolerance mechanical equipment. If there is a slow down or speed up in the document transport velocity, no matter how slight, it will be reflected as an irregularity in the magnetization of a discrete segment in the character field.
It is therefore an objective of the present invention to correlate the position of each discrete segment of a character field in the write station with the timed magnetization of that segment, independent of non-uniformities or inconsistencies in document transport velocity.